Gearbox actuator



FIG. 1 is a top, front, left side perspective view of a gearbox actuator showing the new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a rear elevational view thereof.

The portions of the design depicted in broken lines form no part of the claimed design. 

The ornamental design for a gearbox actuator, as shown and described. 